^ You can call me "bro" ...
Sorry I made a mistake. I thought it was Achiever (which has 15 teeth stock) ...
Actually, Ambition has 14 teeth in front & 38 at rear ... & a 116 links chain.
To increase acceleration, Front sprocket teeth should be less, OR rear should be more. you need a 13 teeth front sprocket, OR a 40 teeth rear sprocket ...
If you go beyond this, gearing would be badly affected ... like top speed/ mileage might suffer a lot.
Now, from HH, only Karizma has a 40 tooth rear sprocket ... You would have to confirm yourself whether it fits Ambition or not... Take a helpful mechanic's help from HH showroom.